Many pesticides and insecticides are known to the art and are important in agriculture as tools for controlling insect pests. Many of the insecticides presently in use however, such as the organophosphorous compounds, the carbamates and the chlorinated hydrocarbons, while effective against insects, have very high mammalian toxicity and some of these materials are believed to have carcinogenic and teratogenic effects. At the present time the insecticidal situation in particular is becoming increasingly controversial because the past use of broad spectrum insecticides such as the chlorinated hydrocarbons to achieve maximum kill of pests, has resulted in excessive pollution of the environment. Moreover, the problem of pesticidal residues in crops with their attendant hazards to human health, the rapid development of insecticide resistant populations, severe effects on non-target species, and rapid changes in status of secondary pests, has created a situation where new pesticidal materials must be provided.
It will be understood that the philosophy of pest control is changing and the strategy now is an integrated approach to pest management utilizing biological, chemical and natural control factors. This approach employs the idea of maximizing natural control forces and using other tactics with a minimum of disturbance to the agro-economic system. Therefore it is important that the new pesticides be selective in their action rather than being the type of material which will achieve maximum kill of pests. Thus the importance of establishing minimum dosage rates for holding pest populations just below economic injury levels are now important.